There are a number of enzymatic activity tests which have used spectrophotometric or fluoremetric methods to enumerate active and inactive microbes [See, for example, Flint, European J. Appl. Microbiol., 4, 195 (1977); Dutton, et al., Wat. Res., 20, 1461 (1986); Burton, et al., Wat. Res., 21, 1173 (1987); "Sediment Microbial Activity Tests for the Detection of Toxicant Impacts" Aquatic Toxicology: Seventh Symposium, ASTM STP R. D. Caldwell, et al., Ed. American Society for Testing and Materials, Philadelphia, 1985 pp. 214-228; Environmental Toxicology and Chemistry, 8, 1057 (1989); Toxicity Assessment, 4, 149 (1989); Toxicity Assessment, 4, 255 (1989); Cloete, et al., Wat. Res., 22, 961 (1988); Wat. Res., 22, 971 (1988); Katayama-Hirayama, Wat. Res., 20, 491 (1986); Obst, Fresnius Z. Anal. Chem 321, 166, (1985); Obst, et al., Toxicity Assessment, 3, 81 (1988)]; and to determine active biomass [See, for example, Teuber, et al., European J. Appl. Microbiol., 4, 185 (1977); Schnurer, Applied and Environmental Microbiology, 43, 1256 (1982); Hoppe, Mar. Ecol. Prog. Ser., II, 299 (1983); and Tan, Marine Biology. 76, 247 (1983).
Fluorescent indicators have been utilized in cats and rats to measure central nervous system pH [See, for example, Sundt, et al., "Umbelliferone as an Intracellular pH-Sensitive Fluorescent Indicator and Blood-Brain Barrier Probe: Instrumentation, Calibration and Analysis", 60 (1980)]. U.S. Pat. No. 4,534,317 discloses fluorescing dyes which are used to monitor fish food consumption.
None of the methodologies disclosed in the art utilizes a series of test concentrations to develop standard LC50 and EC50 toxicity values that are required by the Federal Water Pollution Control Act Amendments (Clean Water Act) of 1977 (PL 95-217). Section 101(a)(3). Nor do any of these methodologies provide a measure of toxicants in an aquatic body in a fast and efficient manner.
The present preferred method for determining aquatic toxicity in water supplies generally utilizes a 48 hour daphnia test or a 96 hour fathead minnow test. In these methodologies, the multicellular organisms are exposed to a toxicant for a period of 2 to 4 days and then the live organisms are counted to determine death rate. Other bioassay tests, which utilize 24 hour to 21-day tests, are described by the United States Environmental mental Protection Agency, ASTM, SETAC, OECD and various other State and private research groups. There is a clear need in the art for a fast, easy to use bioassay test which has reliability and accuracy, and which may be used with confidence by a lay person.
It is an object of the present invention to provide an aquatic bioassay that can be used to measure various toxicants in aquatic sources in an easy, fast and efficient manner.
It is a further object of the present invention to provide a novel aquatic bioassay which ca test both lethal (acute) and sublethal (chornic) concentrations of toxicants in aquatic sources.
It is still an additional object of the present invention to provide a method for determining the concentrations of various toxicants in aquatic sources in a fast, efficient manner.
It is still another object of the present invention to provide a bioassay kit for testing toxicants in aquatic sources.
These and other objects of the present invention may be readily determined by a review of the description and the examples of the present invention.